<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.1/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function(){
var tex = $('#mytable').find('tr:first-child').find('td:first-child').text();
alert(tex);
});
</script>
<table id="mytable" border="2" width="15">
<tr id='first_tr'>
<td>first_column_one</td>
<td>first_column_two</td>
<td>first_column_three</td>
</tr>
<tr id='second_tr'>
<td>second_column_one</td>
<td>second_column_two</td>
<td>second_column_three</td>
</tr>
<tr id='third_tr'>
<td>third_column_one</td>
<td>third_column_two</td>
<td>third_column_three</td>
</tr>
<tr id='fourth_tr'>
<td>fourth_column_one</td>
<td>fourth_column_two</td>
<td>fourth_column_three</td>
</tr>
</table>
<!-- SELECT CONCAT_WS(",","First name","Second name","Last Name"); -->